Microelectrode fabrication by laser direct curing of tiny nanoparticle self-generated from organometallic ink

In this paper, we present a new laser direct patterning method that selectively cures nanoparticles self-generated from organometallic ink by proper thermal decomposition. This approach has several advantages in the curing rate, resolution and pattern quality compared with the conventional nanoparticle ink based direct laser curing method. It was found that a laser wavelength which is more weakly absorbed by the nanoparticles could produce a more stable and homogeneous curing condition. Finally, arbitrary shaped silver electrodes with narrow width and uniform profile could be achieved on a polymer substrate at a high curing rate of 25 mm/s. This process can be applied for flexible electronics fabrications on heat sensitive polymer substrates. (C) 2011 Optical Society of AmericaY

One-Step Fabrication of Copper Electrode by Laser-Induced Direct Local Reduction and Agglomeration of Copper Oxide Nanoparticle

Copper oxide (CuO) nanoparticle-based organic solutions are highly stable in air as well as cheaper compared to copper (Cu) nanoparticle solutions due to the absence of particle oxidation problems. Laser direct patterning via photo-thermochemical reaction of the CuO nanoparticles is suggested to efficiently fabricate Cu electrodes. CuO nanoparticles dispersed in ethylene glycol were instantaneously reduced to Cu nanopartides by intense laser irradiation, and the Cu nanoparticles were simultaneously agglomerated and sintered to form conductors without additional processes. Finally, Cu electrodes with about 10 mu m thickness and a specific electrical resistance of 31 mu Omega.cm were successfully fabricated on a glass and flexible substrate. Furthermore, the maximum possible patterning rate was discussed in terms of the reduction rate of CuO. This conductor structuring method enables an environmentally friendly and cost-effective process as well as a low-temperature manufacturing sequence to realize large-area, flexible electronics on polymer substrates.N

Hybrid subtractive micro-patterning of a self-assembled SiO2 nano/microsphere monolayer

Colloidal self-assembly and direct micro-patterning of functional materials have drawn intense interest as an alternative to the conventional photolithography based microelectronics fabrication process. In this paper, we introduce a facile subtractive micro contact printing method to create a patterned colloidal nano/micro sphere monolayer on a wafer scale by combining an additive 'bottom-up' self-assembly and subtractive 'top-down' printing process. A vacuum-assisted contact printing method enabled precise and uniform pressure control to directly fabricate a large-area micro-patterned hexagonally close packed structure of nano/micro spheres on the target substrate very fast, at low cost, under ambient conditions. In addition, analysis on the hybrid printing pressure and the patterning time has been conducted.N

Nanorecycling: Monolithic integration of copper and copper oxide nanowire network electrode through selective reversible photothermochemical reduction

Laser induced selective photothermochemical reduction is demonstrated to locally and reversibly control the oxidation state of Cu and Cu oxide nanowires in ambient conditions without any inert gas environment. This new concept of "nano recycling" can monolithically integrate Cu and Cu oxide nanowires by restoring oxidized Cu, considered unusable for the electrode, back to a metallic state for repetitive reuse.N